Did you check the bot's IP address to verify that it was a genuine Google bot? Some bots may spoof the googlebot useragent. I've had to block a number of undesirable bots that were sucking up a lot of data transfer using htaccess. That Brandwatch bot hammered my site with up to 8 page requests per second. I emailed the folks over there and requested they stop the bot from spidering my site. They said it would stop but it didn't. Now all it gets is a denied error and zero bytes transfered. If you don't want Chinese traffic, blocking Baidu is a good idea. When I blocked Baidu, the amount of spam I got on my forum dropped. Blocking Baidu, Yandex, and denying referrers from .cn, .ru, and .ua tlds dropped my forum spam to next to nothing. I have only had a few spam posts all year, less than I used to get in a single day. It isn't just data transfer these bots consume, they also use server resources and there is no point in getting into hot water with your host for consuming too much server resources to serve data to bots that do nothing for you.